Rock drill feeding device



May 19, 1931. E. G. GARTIN ROCK DRILL FEEDING DEVICE Filed Aug. 18, 1930 Vknown as a tell-tale,

Patented May 19, 1931 i Unirse-STATES {PAT-ENT oFricE CHINE-BY COMPANY, A CGPCR-ATION QF MASSACHUSETTS ROCK DRILL rnnnnve DEVICE Application filed rAugust 18, r1930.. Serial No. 475,946. i

y My invention relates to rock drill feeding devices, and more particularly to feedingdeyvices of the lrind used in stoping drills. An object of my invention isV to provide anim'- k I n sectionto that "species of the invention; and

provedv feeding devicefor a stoping drill. Another object is to provide an improved feeding device for a stoping drill in which loss of lubricant can be avoided while at theA same time insuring the proper notifica-tion of Y the drill runner that a change in drill steels is necessary. Y.

The usual stoping drill feed has aport and feed piston reach their relative position of maximum extension, in other words, just before the limit of feed is reached. This is very important as it advises the runner that it is necessary to collapse the feed and change the steel. At the same timeiit is a source of difficulty in view of the fact that it seriously interferes with proper lubrication of the feed and results in a considerable loss and waste of lubricant. lt. is custom-V ary to put a substantial quantity of grease or the like into the feed cylinder above the feed piston in direct type feeds, and if itiweie not for the fact that this lubricant is blown out very'promptly through the tell-tale, aVr

small quantity would suffice for lubrication for quite a period. When it is blown out the packings tend todry and sticking occurs. It would therefore be desirable to eliminate the tell-tale if possible or at least to eliminateits disadvantageous effect on the lubrication of the feed.' Itis a specific object of my inven'# tion to accomplish this desiredresult by retaining the Vfunction of the tell-tale, namely .of discharging` a jet of air as the limit of feed is approached, while at the same time preventing' the iiowing out of the lubricant from thel feed cylinder.v Other objects and advantages of my invention will hereinafter subsequently appear. y l f In the accompanying'drawings, in which for purposes of illustration three yforms of the invention are shown, c y

` Fig. 1 Vis a central vertical section thro'ugh a stoper feed mechanism in whichnone species of my invention iis embodied;

motor, not shown,

which is uncovered by the feed piston justbefore the feed'cylinder Fig. 2 is a corresponding view showing the parts in a vdifferent Vrelative, position;

Fig. 3 1s a section on theline 3 3 of Fig. 1; Fig. 4 kis a fragmentaryv view on a similar of Fig. llshowing a second Fig. 5 is a central vertical section showing a third species of the invention.

Referring to theY drawings, 1 represents the block which intervenes between a percussive and the feeding mechanisni, which is generally designated 2. Within the head'block is a throttle valve 3 which controls the supply of air tothe feed* ing mechanism. The feeclingmechanism 2 comprises a feed cylinder 5, a bushing or sleeve 6, which cooperates with parts later `described to retain the feed in collapsed po- 'sition, and a collar 7 which is secured by side rodsor other bolts to'the head block or the drilling motor for the purpose of maintaining the feedand other parts in assembled re# lation. The feed cylinder has at its lower end a heard Sthrough which a bore 9 is formed, and the lower end of the feed cylinder is surrounded by a clamp 10,k throughl which 'nLMn-B. e. GARTIN, or CLAREMONT', iviiwy HAMPSHIRE, .AssrGNoR To SULLIVANY iviaand the head `8, a boltll passes.V The feed yfurther includes within the feedV cylinder 5, afeed piston 13 having 'a piston rod 14 formed of a tubular kmember 15 attached to Vend sleeves 16; `;Tlie lower sleeve carriesa point 17 ,threadedfinto its'flowei end, and the ,upper end ofthe upper sleeve is reduced as at 19 toextend through Vthefeed piston proper,

which comprises a plate 20, an intermediate member 21 and a followerV member 22, there being cup leathers 23 clamped between the member 21 and themembers 20 and 22. The upper end of the reduced portion of piston rod 1li is threaded and Vhas a nut member 25 screwedgthereon and retaining in position a spring 26, which is adapted to enter a bore 27 in the sleeve '6 and yieldingly retain the Vfeed in collapsed position. The reduced extension 19 is provided with a longitudinally extending-bore 29 having an upper portion 30 of larger diameter. Within this bore a valve 31 Vis, vreciprocable; the valve comprising a lower guide stem'32 in the bore 29, an inter-` e;

mediate-'reduced portion 33, and ahead V34 adapted to engage a valve seat 35 at the junction of the enlarged bore and the small bore 29. A spring 36 engages the top of the valve and a stop member 37 mounted transversely of the bore 30, and normally maintains the valve 34 seated upon the seat A passage 38 extends from a point below the valve seat laterally and then downwardly into the interior of the upper sleeve member 16 of the piston rod, and ports open laterally through the walls of the piston rod as at 40, these ports bein arranged in such position that they pass lielow the cylinder head 8 just as the limit of feed is approached. The valve stem 32 projects into a transverse opening 41 formed through the piston rod 14; and a transversely extending pinV 42. lies within this opening and is attached at its opposite ends to a ring or annular member 43. This member 43 is engageable with the upper surface of the lower cylinder head 8 just before the limit of feed is reached, and thus raises the transverse rod or pin 42 and, accordingly,

past the valve 34 through the passage 38 and through the interior of the piston rod out through the passages which at the same time become exposed just below the lower head 8 of the feed cylinder.

From what has been said it will be readily understood that when the feed is nearly completed, thefports 4()l become exposed below the cylinder head 8 and substantially at the same time the ring 43 engages the upper surface of the cylinder head 8 and, as the cylinder head continues to approach the piston, the plunger 32 is raised unseating the valve and permitting air to flow from the axial portion of the feed cylinder through a passage spaced from and above the cup leathers, through a series of passages, and finally out of the ports 40, to serve as a telltale. There is no loss of any substantial amount of lubricant, however, because the lubricant adheres to the cylinder walls and cup leathers, whereas the air which blows outward to notify the drill runner that the feed is fully out comes from the center yor axial portion of the cylinder and not from a point adjacent the cylinder wall. y

In the species of the invention shown in Fig. 4.a valve corresponding in function to the va ve 32 is employed, but it is differently ranged in the piston head and is directly engaged with the lower cylinder head near the end of the feed. In this construction the head block 1, the clamp 7, feed cylinder 5, and sleeve 6 may be the same as in the construction of Fig. 1. The piston rod is of plural part construction and comprises a tubular member 15 attached to a sleeve 16. The sleeve 16 has an enlargement 45 of substantially the full kcross sectional area of the cylinder, and has above thel enlargement, a

the valve 34 and thereby per' .e mits the flow of fluid from the feed cylinder reduced portion 46, surrounded by members 20, 21, 22 and cup leathers 23, of substantially the same construction as the correspondingly numbered parts of Fig. 1. A nut 25 cooperates with a threaded portion at the upper end of the portion 46 to hold the parts together and position a spring ring 26. A passage 48 extends axially through the extension 46 from the upper end of the latter to a point within the enlargement 45. A valve chamber 49 is formed below the plate 2O in the enlargement and a valve 50 is mounted in the chamber. A sleeve 51 provides a seat 52 for the head 53 of the valve and a guide 54 for the stern 55 of the valve. The valve is reduced at 56 just below its-head. Passages 57 and 58 respectively connect the space above the valve head 53 with the passage 48 and the space below the valve head 53 with the hollow bore of the piston rod 15. The stem 55 of the valve projects below the bottom of the enlargement 45 when the valve is seated and is adapted to engage the lower head (not shown) of the feed cylinder just before the end of the forward feed is reached. The piston rod is provided with passages 40' which are located to cause them to be uncovered below the lowerliead of the feed cylinder ust'as the valve stem 55 engages the latter.

i The mode of operation of this form of the invention will also be apparent. It may be summarized by stating that during all but the last portions of the forward feed the head 53 of valve prevents communication between the bore of the feed cylinder above the feed piston and the space within the piston rod 15. When, however, the enlargement 45 and the lower head of the feed cylinder are close enough together, the valve stem is engaged by this cylinder head and the valve 50 permits pressure fluid to pass from the working space in the feed cylinder through passages 48, 57, and 58 and through ports 40, to signal to the drill runner the approach to the limit of feed. The air which serves as a tell-tale, being taken from the axial part of the cylinder bore and from a point substantially spaced from the cup leathers and cylinder walls, carries With it very little lubricant and therefore serves its signalling purpose while lubricant is conserved. l

Fig. 5 discloses a third species of my invention. In this form the piston proper has the valve incorporated in it rather than carrying a separate valve element. The usual head block 1 provided with a suitably controlled passage 4 for the feeding pressure fiuid has secured thereto by a clamp 7 a feed cylinder 5 and also -a sleeve member 6. A feed piston 60 is mounted on the upper end of a piston rod generally designated 61. The latter comprises a tubular member 62 attached to a sleeve 63 and is hollow and traversed by tell-tale ports 64 which are positioned to cause their exposure below the lower head of the feed cylinder just before i the limit of forward feed is attained. The y rod structureincludes a shoulder 65 and a reduced portion (i6-,the latter having at its upper end a. threaded portion67 supporting ka nut 68 which carries a spring 69 adapted to cooperate with the sleeve member-6 to lie-ep the feed in collapsed position during transport. Slidable on the reduced Vportion 66 is the piston structureproper, andvtliis comprises a lower plate 72 engaging 'theshoulder 65, an intermediate member 7 3 and a YtopV Tmember 74, cup washers being mounted bethrough the cylindricalV wall of the reduced portion 66. The intermediate member 7 3 has an internal groove 77, normally communicating only with the passage 76 but adapted on relative longitudinal movement between` s the piston and its rodto connect the passages 75 and 76 and permitl flow' of pressure uid from the interior of the feed cylinder through passage 75, groove 77, passage 76 and ports 64 to the atmosphere.

rlhe operationk of this form of the invention will be obvious from the description given.k During the major part of feeding movement the piston will engage the shoulder 65 and no air will reach the ports` 64, When the feed piston contacts with the lower head ofthe feed cylinder, relative move 'l ment betweenthe'piston and piston rod will V take place and the groove 77V will connect the passages 75 and 76 and air will flow from the feed cylinder to the port 64:V and notify the operatorthat the limit of feed is reached. Obviously, however, no Ymaterial loss of lubricant will occur, due to the locus of the inlet to the passage 75.5V

From the foregoing description of several ofthe different forms whichmy invention may assume in practice, it will be evident that I yhave provided an improved feeding mechanism which retains theV familiar signal of the usual tell-tale, but which prevents the very rapid loss of lubricant which hasV been found tov attend upon the use of the if tell-tale'port as usually arranged. Moreover, my improved arrangements are simple, rugged, not easily damaged, and require no` f attention not ordinarilyfaccorded the drilling device by the runner. Y

While there are inV this application spe-` cifically described three forms which the in- AVention may assume in practice, vit will be the limit of feed'. Y

understood that these forms are shown for purposes of 4illustration. and that ythe inventionfniay be modified and embodied in various other forms without departing from itsspirit orthescopefof'theappended claims.

VhatI claim as new and desireto secure by Letters Patent is: Y

1.-`:Ina drilling mechanism, relatively movable feed `cylinder and piston elements,

the latter having rapiston1rod,and means for indicating the attainment of maximum extension between thecylinder and piston includingfa tell-tale port in the piston and inea-ns for supplyingair thereto only at about i 2., In a drilling mechanism, feedcylinder, a feedl piston reciprocable therein, andk means for'indicatin'g the attainment of maximum relative movement therebetween includ in@ tellet'ale; ortand means for conducting n p b lluidthereto from the cylinder borecommu- -nicatingwith :the bore fof said cylinder only adjacent the jaxis thereof. y

'3. .In v'a'` drilling mechanism, a feed cylinder, a feed piston in said cylinder, atell-tale portpand lmeans 'for ,controlling iiuid iiow thereto including a valve supported by said '2 4. In af drilling.iiiechanisnnV a feed cylinder,a feed piston therein having a piston rod, a-tell-tale port, and means controllingrlow lof-fluid.throughsaid port including a4 valve movable relative to said piston rod.

. 5. In a drilling mechanism, a feed cylinder, afeed piston therein having ay piston rod, a tell-tale'port, and meansy controlling flow of fluid through said tell-tale port includinga lvalve within-said piston movable relative to said pistonrod. 1

6. In a drilling mechanism@ feed cylinder,

a feed Vpiston thereinfhavingv a piston rod, a tell-tale port, and means forcontrolling flow of fluid throughsaid tell-'tale port including a valve movable? relative to said piston and piston rod.`v j Y f 7. In' a drilling mechanism, a feed cylinder, a feedpiston thereinV having -a piston rod, a tell-tale port, and means for controlling iiow of fluid through said tell-tale port including a valve coaxial with said piston rod.

ies

8. In a drilling mechanism, a feed cylinder, Y

a feedpiston therein having a piston rod, a tell-ta-lerpoit, and means for controlling flow of fluidthrough said port including a valve at the axis of said rod.

9. In a drilling mechanism, afeedcylinder, arefeedy piston therein having a piston rod, a

tell-tale port, and meansfor controlling flow A of fluid through said'portincluding a sleeve valve coaxial with said pistonrod.

A 10. VIn adrilling mechanism, a feed cylinder, a feed piston therein having a Apiston rod,`

tell-tale port, and lmeans nfor controlling flow of fluid through said port including al valve parallel to the axis of said piston rod.

11. In a drilling mechanism, a feed cylinder, a feed piston therein having a piston rod, a tell-tale port, and means for controlling` flow of fluid through said port including a valve operated by relative movement between said piston and cylinder.

12. In a drilling mechanism, a feed cylinder, a feed piston therein having a piston rod, a tell-taleport, and means for controlling 10 flow of fluid through said port including a valve operated by relative movement between said piston and piston rod.

13. In a feeding mechanism, a feed cylinder, a feed piston therein having a piston rod,

1;, said piston rod having a tell-tale port therein, and means for controlling flow of fluid to said port including a passage opening. into the cylinder bore adjacent the axis of the latter, and a valve reciprocable longitudinally of g4) the cylinder for controlling flow of fluid in said passage.

14. In a feeding mechanism, a feed cylinder, a feed piston therein having a piston rod,

said piston rod having a tell-tale port therein,

2,-, and means for controlling flow of fluid to said port including a passage opening into the cylinder bore adjacent the axis of the latter, and a valve reciprocable longitudinallv of the cylinder for controlling flow :ic of fluid in said passage, said valve having a stem and said cylinder having associated therewith means engageable by said stem as the limit of feed is approached.

15. In a feeding mechanism, a feed cylin- :-.5 der, a feed piston therein having a piston rod, said pist-on rod having a tell-tale port therein, and means for controlling flow of fluid to said port including a passage opening into the cylinder bore adjacent the axis 40 of the latter, and a valve reciprocable longitudinally of the cylinder for controlling flow of fluid in said passage, said cylinder and valve having elements associated therewith cooperating to effect opening of said valve 45 when the limit of feed is approached.

In testimony whereof I aflix my signature.

ELMER G. GARTIN. 

